%0 Journal Article %1 PhysRevB.103.024521 %A Timm, Carsten %A Brydon, P. M. R. %A Agterberg, Daniel F. %D 2021 %I American Physical Society %J Phys. Rev. B %K a %N 2 %P 024521 %R 10.1103/PhysRevB.103.024521 %T Distortional weak-coupling instability of Bogoliubov Fermi surfaces %U https://link.aps.org/doi/10.1103/PhysRevB.103.024521 %V 103 %X Centrosymmetric multiband superconductors which break time-reversal symmetry generically have two-dimensional nodes, i.e., Fermi surfaces of Bogoliubov quasiparticles. We show that the coupling of the electrons to the lattice always leads to a weak-coupling instability of such a state toward spontaneous breaking of inversion symmetry at low temperatures. This instability is driven by a Cooper logarithm in the internal energy but the order parameter is not superconducting but distortional. We present a comprehensive symmetry analysis and introduce a measure that allows us to compare the strengths of competing distortional instabilities. Moreover, we discuss the instability using an effective single-band model. This framework reveals a duality mapping of the effective model which maps the distortional order parameter onto a superconducting one, providing a natural explanation for the Cooper logarithm and the weak-coupling nature of the instability. Finally, we consider the possibility of a pair-density wave state when inversion symmetry is broken. We find that it can indeed exist but does not affect the instability itself.

@article{PhysRevB.103.024521, abstract = {Centrosymmetric multiband superconductors which break time-reversal symmetry generically have two-dimensional nodes, i.e., Fermi surfaces of Bogoliubov quasiparticles. We show that the coupling of the electrons to the lattice always leads to a weak-coupling instability of such a state toward spontaneous breaking of inversion symmetry at low temperatures. This instability is driven by a Cooper logarithm in the internal energy but the order parameter is not superconducting but distortional. We present a comprehensive symmetry analysis and introduce a measure that allows us to compare the strengths of competing distortional instabilities. Moreover, we discuss the instability using an effective single-band model. This framework reveals a duality mapping of the effective model which maps the distortional order parameter onto a superconducting one, providing a natural explanation for the Cooper logarithm and the weak-coupling nature of the instability. Finally, we consider the possibility of a pair-density wave state when inversion symmetry is broken. We find that it can indeed exist but does not affect the instability itself.}, added-at = {2021-04-11T12:24:06.000+0200}, author = {Timm, Carsten and Brydon, P. M. R. and Agterberg, Daniel F.}, biburl = {https://www.bibsonomy.org/bibtex/2b19918220feaca07e9d66bbc704533b7/ctqmat}, day = 21, description = {Phys. Rev. B 103, 024521 (2021) - Distortional weak-coupling instability of Bogoliubov Fermi surfaces}, doi = {10.1103/PhysRevB.103.024521}, interhash = {24ee32ac285e317147e6514e2467f359}, intrahash = {b19918220feaca07e9d66bbc704533b7}, journal = {Phys. Rev. B}, keywords = {a}, month = {01}, number = 2, numpages = {21}, pages = 024521, publisher = {American Physical Society}, timestamp = {2023-01-16T14:49:29.000+0100}, title = {Distortional weak-coupling instability of Bogoliubov Fermi surfaces}, url = {https://link.aps.org/doi/10.1103/PhysRevB.103.024521}, volume = 103, year = 2021 }